diff --git a/src/main/bio2/bi2a-iidx.h b/src/main/bio2/bi2a-iidx.h
index 6248128..78fba49 100644
--- a/src/main/bio2/bi2a-iidx.h
+++ b/src/main/bio2/bi2a-iidx.h
@@ -30,7 +30,7 @@ struct bi2a_iidx_panel {
     uint8_t y_start1 : 1;
 };
 
-struct bi2a_iidx_state_out {
+struct bi2a_iidx_state_in {
     struct bi2a_iidx_slider SLIDER1;
     struct bi2a_iidx_system SYSTEM;
     struct bi2a_iidx_slider SLIDER2;
@@ -84,7 +84,7 @@ struct bi2a_iidx_light {
     uint8_t l_state : 1;
 };
 
-struct bi2a_iidx_state_in {
+struct bi2a_iidx_state_out {
     struct bi2a_iidx_light UNK1[3];
     struct bi2a_iidx_light PANEL[4];
     struct bi2a_iidx_light DECKSW[14];
@@ -96,11 +96,11 @@ struct bi2a_iidx_state_in {
     uint8_t UNK3[7];
 };
 _Static_assert(
-    sizeof(struct bi2a_iidx_state_in) == 48,
-    "bi2a_iidx_state_in is the wrong size");
-_Static_assert(
-    sizeof(struct bi2a_iidx_state_out) == 46,
+    sizeof(struct bi2a_iidx_state_out) == 48,
     "bi2a_iidx_state_out is the wrong size");
+_Static_assert(
+    sizeof(struct bi2a_iidx_state_in) == 46,
+    "bi2a_iidx_state_in is the wrong size");
 #pragma pack(pop)
 
 #endif
diff --git a/src/main/bio2emu-iidx/bi2a.c b/src/main/bio2emu-iidx/bi2a.c
index c43e0e4..733827f 100644
--- a/src/main/bio2emu-iidx/bi2a.c
+++ b/src/main/bio2emu-iidx/bi2a.c
@@ -188,8 +188,8 @@ static void
 bio2_emu_bi2a_send_state(struct ac_io_emu *emu, const struct ac_io_message *req)
 {
     struct ac_io_message resp;
-    struct bi2a_iidx_state_out *body;
-    struct bi2a_iidx_state_in *req_bi2a;
+    struct bi2a_iidx_state_in *body;
+    struct bi2a_iidx_state_out *req_bi2a;
 
     uint8_t input_sys = 0;
     uint8_t input_panel = 0;
@@ -204,8 +204,8 @@ bio2_emu_bi2a_send_state(struct ac_io_emu *emu, const struct ac_io_message *req)
     resp.addr = req->addr | AC_IO_RESPONSE_FLAG;
     resp.cmd.code = req->cmd.code;
     resp.cmd.seq_no = req->cmd.seq_no;
-    resp.cmd.nbytes = sizeof(struct bi2a_iidx_state_out);
-    req_bi2a = (struct bi2a_iidx_state_in *) req->cmd.raw;
+    resp.cmd.nbytes = sizeof(struct bi2a_iidx_state_in);
+    req_bi2a = (struct bi2a_iidx_state_out *) req->cmd.raw;
 
     packed_lights.panel_lights = 0;
     for (size_t i = 0; i < 4; ++i) {
@@ -246,8 +246,8 @@ bio2_emu_bi2a_send_state(struct ac_io_emu *emu, const struct ac_io_message *req)
         return bio2_emu_bi2a_send_status(emu, req, 0);
     }
 
-    body = (struct bi2a_iidx_state_out *) &resp.cmd.raw;
-    memset(body, 0, sizeof(struct bi2a_iidx_state_out));
+    body = (struct bi2a_iidx_state_in *) &resp.cmd.raw;
+    memset(body, 0, sizeof(struct bi2a_iidx_state_in));
 
     // IIDX25 polls really really fast, this limits it to 1000Hz
     if (poll_delay) {